1. Field of the Invention
This invention relates to a fire extinguisher especially a hand-held portable fire extinguisher. More particularly, this invention provides a means of insuring that the extinguisher has not been tampered with or inadvertently discharged.
2. Discussion of the Prior Art
Numerous means for sealing fire extingushers to prevent tampering or inadvertent discharge have been provided. Such a device is disclosed for instance in U.S. Pat. No. 3,666,016 wherein a plastic pull ring is provided having a strand with resilient, relatively thin sections including a group of wedge-shaped fingers. Such a strand is described in U.S. Pat. No. 3,467,427.
The pull pin passes through the plunger and is held in place by a sealing member disposed on the exterior of the plunger opposite to the entry point of the pin. In operation, the pin is pulled which causes a thin section of the strand or the exterior sealing member to break.
Such a device requires a specially molded and dimensioned pin having a notched tip and a specifically sized and dimensioned sealing member which protrudes from the side of the plunger of the fire extinguisher. In operation, a distinct disadvantage is realized. The pull pin is severed principally at points of weakness. Since this is the weakest point of the pin, it means that even upon sever of the pin there is a likelihood that a portion of the pin shaft can remain in the channel through which it has passed to prevent the immediate discharge of the fire extinguisher.
It has therefore become desirable to provide a tamper proof fire extinguisher in which the seal is broken upon actuation of the plunger thereby permitting the contents of the cylinder of the fire extinguisher to be immediately discharged. Moreover, it has become desirable to provide such a system whereby manual pin removal is not required. It has become particularly desirable to provide a sealing system which eliminates externally disposed pull pins.